Alkali resistance test

Orienting test to assess the alkaline resistance of the skin, especially in toxic-degenerative eczema.

3 adjacent areas of skin (usually on the back of the hand or the forearm flexion side) are each wetted with 1 drop of 0.5 normal NaOH solution and each covered with a small glass block. After 10 minutes, one glass block is completely removed; another drop of the above-mentioned solution is dropped under the two remaining blocks. After a further 10 minutes, the second glass block is also removed; only under the last ones is another drop of the above-mentioned solution placed, before this glass block is also removed after a total of 30 minutes. Skin reactions in form of erythema, infiltrate, papules or erosion already after 10 or 20 minutes indicate a reduced alkaline resistance of the skin.

Occasionally, if the skin's resistance to alkalis is greatly reduced, significant, toxic skin damage ( erosion) can occur. S.a. Alkaline neutralisation test and nitrazine yellow test.